i have a 2000 ford focus, 2 years ago my heater blower stopped working on speed 1 2 3 it would only work on 4, i found out the resistor was the problem changed it an all was ok. The problem re occured 2 months ago so i replaced the resistor again and all was ok, now the problem has re occured, the heater fan only works on speed 4, i suspect the resistor has gone but something must be causing it as its only 2 months old. Any help would be much appretiated,,,,thanks.